Under which scenario might a bone biopsy not be required?

• A. If signalment and signs suggest a primary bone tumor and radiographs are consistent
• B. If the owner opts for no treatment or palliative amputation regardless of diagnosis
• C. If imaging suggests a bone biopsy could precipitate pathologic fracture
• D. If serology confirms fungal osteomyelitis

Answer: (A)

If the dog's or cat’s age and clinical signs, along with radiographs, create a very strong impression of a primary bone tumor and the imaging findings are classic for that diagnosis, a biopsy may not change the planned management. In such a scenario, proceeding with treatment (for example, amputation or limb-sparing surgery with adjunct therapy) without histologic confirmation can avoid delaying care and spares the patient from biopsy risks, since the likely diagnosis is already established and the chosen therapy would be the same regardless of the exact histology.

The other situations either rely on tissue confirmation to guide therapy or carry reasons why biopsy remains valuable: uncertainty about the diagnosis, the need to tailor treatment to a specific infective or inflammatory process, or scenarios where biopsy would not only be unnecessary but also risky or unlikely to alter outcomes.